AT&T to lead Windows Phone 7's US touchdown

Microsoft is teaming up with premier partner AT&T for Windows Phone 7's US coming-out party next Monday.

Chief executive Steve Ballmer will host the press event at its New York City technology center along with AT&T mobility and consumer markets CEO Ralph de la Vega, where they will preview Windows Phone 7 devices from different handset makers.

The event is designed to shine the light on Microsoft's partnership with US number-two carrier AT&T, which Microsoft has nailed as a premier partner for Windows Phone 7.

Contrary to earlier reports, it now seems that number-three US carrier T-Mobile won't be the "star" of the event — but it might participate in a lower capacity later in the day.

T-Mobile will appear at an OEM-showcase of phones scheduled for after the big AT&T flag-waver.

The event runs from 9am to 5pm Eastern Time, with the AT&T press conference starting at 9:30. T-Mobile had been listed in an earlier event invitation from Microsoft here (thanks All Things D's John Paczkowski) as being on hand between 3:30 and 4:30 to present devices — but the current version has erased T-Mobile's name. The earlier text had read:

T-Mobile reps will be present for device showing and their service offering discussion / Microsoft developer architect will demonstrate Windows Phone 7 applications

Given that AT&T is the designated premier partner, it would have been extremely bad politics for a rival carrier's name to have made it onto the billing.

That said, when Windows Phone 7 is available for purchase, AT&T won't be the exclusive provider in the US — expect phones from T-Mobile, as well.

Welcome to the arena of carrier politics, where the frailty of the egos is matched only by the might of the muscles.

Microsoft's event, meanwhile, is shaping up as something designed to generate blogospheric coverage for Windows Phone 7. Phones won't actually be available for sale on October 11 — that's expected on November 8. AT&T, and later T-Mobile, will simply show off their forthcoming phones next Monday.

Separately, Microsoft has opened early submissions of Windows Phone 7 applications to its Windows Marketplace. Developers have until October 6 to submit applications for certification in time for the October 11 launch. ®